Fructose and Fructans in Irritabla Bowel Syndrome (FABS)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government.
Read our disclaimer for details.

The purpose of the study is to investigate if patients with Irritable Bowel Syndrome (IBS) who also report bloating are more likely to report clinically important gastrointestinal symptoms after consuming fructose or fructans than after consuming glucose. We will also use MRI imaging to investigate the mechanisms by which those symptoms might be caused.

We will also study a parallel group of age and gender frequency matched healthy volunteers to provide descriptive statistics on a likely reference range for the healthy population.

Irritable Bowel Syndrome (IBS) is a common chronic condition, the main features of which are pain in the abdomen, an erratic bowel habit and sometimes bloating. Recent research has found that certain carbohydrates (sugars) in the diet can cause symptoms such as discomfort, bloating and wind/gas in people with IBS. These sugars are not well digested in the small bowel. They move to the colon (large bowel) where bacteria act on them by fermentation, producing gas. Some of the gas is absorbed and breathed out through the lungs, where we can measure it. The rest is released as flatulence/ wind, or occasionally belching. People without IBS rarely get symptoms after consuming these sugars. We want to find out what is different in IBS sufferers.

We will study fructose and fructans, sugars found in fruit, vegetables and wheat. Fructose draws water into the small bowel but fructans do not so we can compare effects on the small bowel and colon. Participants will attend three times, and on each occasion consume a drink containing either fructose, fructans, or glucose - a sugar that does not cause symptoms. Neither they nor the investigators present will know which drink is which. They will record their symptoms over the next 5 hours. We will observe how many report a clinically important increase in symptoms.

To look at what is happening in the bowel we will use a technique called Magnetic Resonance Imaging (MRI). We want to see if more gas, or water, builds up in people with IBS than in healthy volunteers. We will also measure the amount of hydrogen released in the breath to see if this is could be a simple bedside test that agrees with the MRI findings

Finding differences between the response of participants to fructose, fructans and glucose could change the way we advise patients, and could lead to the use of MRI as a test for IBS.

We will add together scores for each symptom to get the total score (min 0; max 400). Measurements will be taken at hourly time points from before intervention to 5 hours post-intervention, and an area under the curve (AUC) will be calculated. Measurements will also be taken at intermediate timepoints to better identify the onset of symptoms. Other summary statistics such as peak and time to peak will be reported as appropriate.

Breath Hydrogen [ Time Frame: 0-5 hours after intervention ]

Excretion of H2 (hydrogen) gas in breath, measured in parts per million (ppm). Measurements will be taken at hourly time points from before intervention to 5 hours post-intervention, and an area under the curve (AUC) will be calculated. Measurements will also be taken at intermediate timepoints to better identify the start of the rise in breath hydrogen. Other summary statistics such as peak and time to peak will be reported as appropriate.

Colonic Gas Volume [ Time Frame: 0-5 hours after intervention ]

Volume of gas in the colon as measured on MRI, in millilitres (ml). Measurements will be taken at hourly time points from before intervention to 5 hours post-intervention, and an area under the curve (AUC) will be calculated. Other summary statistics such as peak and time to peak will be reported as appropriate.

Small Bowel Water Content [ Time Frame: 0-5 hours after intervention ]

Volume of free water in the small bowel, as measured by MRI imaging in millilitres (ml). Measurements will be taken at hourly time points from before intervention to 5 hours post-intervention, and an area under the curve (AUC) will be calculated. Other summary statistics such as peak and time to peak will be reported as appropriate.

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Ages Eligible for Study:

18 Years to 65 Years (Adult, Older Adult)

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Criteria

Inclusion Criteria:

Patients who meet the Rome III research diagnostic criteria for IBS(Longstreth 2006) who also report bloating OR

Healthy volunteers who do not meet Rome III clinical diagnostic criteria for IBS

Aged 18-65

Able to give informed consent

Exclusion Criteria:

Any reported history of gastrointestinal surgery (excluding appendicectomy or cholecystectomy)

Unable to stop drugs known to alter GI motility including mebeverine, opiates, monoamine oxidase inhibitors, phenothiazines, benzodiazepines, calcium channel antagonists during or in the 2 weeks prior to the test. (Selective serotonin reuptake inhibitors and low dose tricyclic antidepressants will be recorded but will not be an exclusion criteria)

Antibiotic or probiotic treatment in the past 4 weeks

Inability to lie flat or exceed scanner limits of weight <120kg

Poor understanding of English language

Participation of any medical trials for the past 3 months

Judgement by the PI that the candidate who will be unable to comply with the full study protocol e.g. Diabetes, severe Chronic Obstructive Pulmonary Disease(COPD)